1. Field of the Invention
The present invention relates to an image communication apparatus, a server apparatus, and a capability exchanging method.
2. Description of the Related Art
In conventional facsimile apparatuses, a G3 facsimile apparatus, which carries out data communications using an analog network, and a G4 facsimile apparatus, which carries out data communications using a digital network such as ISDN, etc., are generally used. Such facsimile apparatuses using the analog network and the digital network (hereinafter referred to as xe2x80x9cpublic switched telephone network (PSTN)xe2x80x9d in a word) are hereinafter called G3/G4 FAX. On the other hand, an Internet facsimile apparatus (hereinafter referred to as xe2x80x9cIFAXxe2x80x9d), that receives and transmits data over an Internet protocol, has been developed in recent years. Particularly, standardization of an e-mail type IFAX, which receives and transmits image data using an e-mail transfer protocol, has been developed in IETF (Internet Engineering Task Force) and ITU (International Telecommunication Union).
The following will explain the case using SMTP (simple mail transfer protocol) and POP (Post Office Protocol) 3 as a mail transfer protocol in transmitting data by an e-mail type IFAX.
IFAX transmits a mail to a SMTP server. The SMTP server transfers the mail to a POP3 server to which a receiver belongs. The POP3 server stores the mail in a mail box of a destination.
Since data communications by IFAX is non-synchronously carried out, capability exchange cannot be executed between IFAX and a communication terminal on the destination. For this reason, IFAX is intended to surely carry out communications by executing communications using a minimum function of a transmitter(sender) and the destination(receiver). As described in a document RFC2305 xe2x80x9cA Simple Mode of Facsimile Using Internet mailxe2x80x9d (K. Toyoda et. al; March 1998) issued by IETF, the minimum function, which IFAX should possess, is defined as a xe2x80x9csimple modexe2x80x9d.
More specifically, the communication protocol is SMTP, and corresponds to MIME and a minimum set of a TIFF file.
The minimum set is defined in the above RFC2305. In the TIFF file, there are five sets such as S, F, J, L, and M, depending on a facsimile mode and a profile supporting the TIF file. Among these sets, the lowest one is the profile S, that is, the minimum set.
More specifically, the following points can be defined.
The minimum set supports a monochrome image.
A compression format is a MH (Modified Huffman coding);
A CPU is an Intel system;
A width of paper is 1728 (corresponding to A4 size);
Resolution is 100 dpi or 200 dpi; and
A data list is LSB.
However, in communications using the simple mode, only the minimum function can be used. For this reason, even if both a transmitter terminal and a destination terminal have the function more than the simple mode, communications is carried out using the minimum function.
To solve such a problem, there is considered a communication system in which capability information of destination terminals is registered in a server in advance such that the sender terminal can obtain capability information of the destination terminals from the server. For example, in the Unexamined Patent Publication No. Hei 10-334007 (corresponding to U.S. patent application Ser. No. 09/084,938 filed on May 28, 1998), such a communication system is disclosed. According to IFAX described in the above publication, since capability information of the destination terminals can be obtained before transmission is started, communications suitable for the capability of the destination terminals can be carried out.
However, since it is actually difficult to register capability information of all terminals existing on the Internet to one server, capability information of only the limited terminals is registered to the server. For this reason, when capability information of the destination terminal is not registered in the sever, there is nothing other than the way in which the function is reduced to the minimum function and communications is carried out in a simple mode.
An object of the present invention is that capability information of a destination terminal can be surely obtained by a terminal on a transmitter side, and that the same capability exchange as that of G3 facsimile apparatus can be carried out by an Internet facsimile apparatus.
When an image communication apparatus of the present invention requests capability information of a destination terminal from a first server and no capability information of the destination terminal is registered in the first server, the image communication apparatus requests capability information from a second server having capability information of a network terminal registered in advance or a server group directly or via the first server.
According to the present invention, even if no capability information of the destination terminal is registered in the first server, capability information is requested from the second server having capability information of the network terminal registered in advance or the server group. As a result, capability information of the destination terminal can be surely obtained and communications suitable for the capability of the destination terminal can be carried out.
The above object can be achieved by an image communication apparatus having capability obtaining means for making inquiry to the other server so as to obtain capability information in accordance with the other server when inquiry about capability which a destination possesses is made to one server and the one server has no capability information of the destination; and a data transmitting section for making an image to be suitable for the capability of the destination so as to transmit the image to the destination via the Internet.
Also, the above object can be achieved by an image communication apparatus having first obtaining means for obtaining destination information of a communication counterpart from a first table storing destination information including addresses of a plurality of communication apparatuses and their capability information; second obtaining means for obtaining destination information of the communication counterpart from a second table storing the same information as that of the first table and being capable of obtaining capability information for a shorter period of time than the first obtaining means; control means for operating the first obtaining means when no desired destination information can be obtained by operating the second obtaining means; data processing means for executing processing for converting image data to a format adjusting to capability of the destination; and a data transmitting section for sending transmitting data including the converted image data to the destination via the Internet.
Moreover, the above object can be achieved by a server apparatus having a capability information storing section for storing at least one of a mail address of an image communication apparatus and a telephone number in association with capability; and a capability information providing section for providing capability information in accordance with inquiry from the image communication apparatus.
Further, the above object can be achieved by a capability exchange system wherein capability information of a communication apparatus on the Internet is spread and managed by a plurality of server apparatuses scattered on the Internet, and capability information is sent in response to inquiry about capability sent from the communication apparatus using a mail address by a cooperative operation of the plurality of server apparatuses.
Furthermore, the above object can be achieved by a capability exchange method for making inquiry to the other server so as to obtain capability information in accordance with the other server when inquiry about capability which a destination possesses is made to one server and the one server has no capability information of the destination.